The present invention relates to programmable logic controllers (PLC) and I/O (input/output) product network interfacing methods, and more particularly to methods for interfacing such devices to larger computer networks, such as the Internet.
AL Small programmable logic controllers (PLCs) and I/O products are known that communicate to other PLCs via a host of specialized networks, or via dedicated ports to configuration and monitoring devices. These specialized networks and dedicated ports can be used to provide data and programming for the devices connected thereto. However, the reach of specialized networks is usually limited. The Internet provides global or nearly global coverage, and can be reached by literally millions of personal computers (PCs). Users have come to accept and understand the look and feel of Internet browsers, and have come to expect that all of the information they need to perform their work tasks are available to them via these browsers. Nevertheless, only rarely are small PLCs and I/O products connected to information networks such as Ethernet or Internet infrastructure networks, because such connections are too resource-costly. One known device communicates directly with the Internet using a web browser, and thus requires that the overhead associated with the Internet network interface and web browser be built into the device.
It would be advantageous to combine I/O and PLC communications with the Internet's wide reach and ability to supply information, and to do so without adding significantly to the overhead burden of these small devices. It would further be advantageous to provide the capability of providing users with the “look and feel” of a PC-Internet interface.